HOUGHTON, Mich. — The oldest gray wolf at Isle Royale National Park has been killed, apparently by newcomers to the Lake Superior island chain, researchers said Friday.
The 12-year-old male was one of two survivors that remained when officials decided to relocate wolves from the U.S. and Canadian mainland to rebuild the dwindling population.
His body was found in October. A necropsy showed it had been attacked by fellow wolves, park officials said in a statement.
"With the death of the island-born male, travel patterns of the remaining (mostly relocated and newly arrived) wolves are likely to change significantly, and probably dependent on whether or not the island-born female is still alive, whether she is territorial and how she gets along with the newcomers, both males and females. She is the final native wolf, never radio-collared, and searching for her will be a priority during the upcoming winter study," commented Rolf Peterson, a research professor at Michigan Technological University and long-time wolf and moose investigator on Isle Royale.
The fate of that 10-year-old female is yet unknown.
“She is the final native wolf, never radio-collared, and searching for her will be a priority” for biologists during their annual winter study at the park, said Rolf Peterson, a research professor at Michigan Technological University.
Another female — one of the animals taken to Isle Royale beginning in fall 2018 — also died in recent months from wounds inflicted by one or more wolves.
“These events are not uncommon as wolves defend and establish their territories and social hierarchy,” the park statement said.
The current population includes eight males and seven females. Researchers monitoring the other wolves' radio collars say they are feeding, traveling and sleeping near each other in various combinations, although none of the groups yet meet the scientific definition of a pack.
“We have a unique opportunity to look simultaneously at the past and future of Isle Royale wolves’ genetic health. With the death of M183, we can now more fully understand how genetic isolation and inbreeding impacted the historic wolf population and use that to better monitor the new founders. This is an exciting time and we will be using cutting-edge genetic tools to track reproduction, inbreeding, and genetic change through time, hopefully providing a piece of the puzzle for maintaining a thriving Isle Royale wolf population,” said Dr. Kristin Brzeski, wildlife geneticist at Michigan Tech University.
The National Park Service and the Isle Royale research group say a wolf ‘group’ is characterized by two or more wolves traveling and feeding together. Wolf groups are further defined as a ‘pack’ if groups of two or more wolves are traveling together and/or defending a territory, and if a breeding pair reproduces.
Individual preferences for mating and group or pack formation can be quite variable for a social animal like the wolf. Mate selection and pair bond formation can occur at any time, but wolves only breed and produce pups once per year. Consequently, pack formation can take time. Based on these definitions, there are currently no wolf packs on Isle Royale.
